I guess it depends on if they turn coward. Someone I know that served in Vietnam said that if a West Point gung ho guy started pushing them to do things that they deemed to dangerous or exposed them, often were killed by friendly fire. He said they trusted their sargents more than their leutenants who had no real experience in the type warfare they were fighting. If someone was openly gay and aggressively pushing it, he might be caught in friendly fire.
It was called fragging. You have to understand that today's soldier is a different breed than that of Vietnam. In Vietnam we had a ton of people drafted, many who either didn't want to be soliders, or should have never been trusted on the field in the first place (and those two groups aren't mutually exclusive - there is some overlap). Hence the breakdown of nearly all values and civility of our military at the time. Rather than truly fighting a war, what we had was a ravel of people hooting and hollering, thinking with their limited scope of what was going on that they knew better what to do than the officers, and intentionally killing some officers who "got in the way" (not to mention committing some of the most embarrassing atrocities ever committed by US armed forces).
The simple reality is that the foot soldiers, though their effort and dedication is appreciated, really DON'T know how to fight a war. You can't from that vantage point. They shoot and go where they're told, but that perspective doesn't afford them any special knowledge about what "needs to be done" on the battlefield. That information is more high level, and is EXACTLY the type of thing officers and higher ups would know about.
In effect, I wouldn't point to Vietnam as a particularly good example of the way things are, and certainly not the way they need to be (no offense to any who served at that time - not saying that everyone at that time was doing bad stuff - just that it was pretty rampant - if you were doing what you needed to do then the criticism isn't directed towards you). That conflict (war was never officially declared) single handedly proved why a draft is a bad idea.
Today's military is far more professional. The soldiers who are there by their choice, and in general our culture has simply improved from the Vietnam era. Particularly in the age bracket that encompasses many soldiers, people really just don't care that much anymore whether a person is gay. If you're not gay yourself, you have nothing to worry about. Not to mention that the stereotypical effeminate flamboyant gay that so many seem to refer to is only a tiny minority of the overall population, and it specifically is a segment that probably wouldn't be interested in joining the military. As a matter of fact, take a peak at "The Real World: Philidelphia" (Season 15). Two of the participants in that season of the show were openly gay. One, William, was the type you're referring to - completely effeminate, shopping, "Queer Eye for the Straight Guy" type of personality. The other, Karamo, was not. The other characters didn't even know he was gay for quite a ways into the show, and he talked about several times in the show how he considered effeminate gays unattractive.
Overall, the sky isn't going to fall. What two consenting adults do isn't going to hurt you. Heck I don't see why guys would be bothered by gay men in the first place. Every time two of them hook up that's two potential competitors taken out of the dating game. More ladies left to go around to the rest of us
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